System for synchronizing sound with motion pictures



y 1935. E. H. HANSEN 2,002,111

7 SYSTEM FOR SYNCHRONIZING SOUND WITH MOTION PICTURES iled Aug. 25, 1933Proec "r JOX'LM K. H Camera.

Loud Speaker Patented May 21, 1935 UNITED STATES SYSTEM FORSYNCHRONIZING SOUND WITH MOTION PICTURES Edmund H. Hansen, Los Angeles,Calif.

Application August 25, 1933, Serial No. 686,794

3 Claims.

This invention relates to the art of sound pictures and dealsparticularly with a system for synchronizing sound records with motionpictures. v 1

The purpose of the hereinafter described invention is to provide asimple inexpensive device whereby the small camera or projector nowfinding use in the home and elsewhere may be utilized to record andreproduce actual sound pic- 10 tures.

Briefly stated, the invention comprises means whereby a motion picturecamera or a projector may be driven directly by the same means thatrotates the sound record on a phonograph.

In its preferred form the invention may embody a member adapted to becoupled to and driven by the centering pin of a disk record on aphonograph. The member in this form may carry two units, one a feedscrew for controlling the travel of the sound headand the other aflexible connection for driving a camera or a projector. The member withthese two units may be used for either recording sound in conjunctionwith a motion picture camera or for reproducing sound in synchronizationwith a pro- 'jector.

In another form which may be used for synchronizing sound records withmotion pictures for reproduction purposes, the invention may embody onlya flexible drive connection for driving a pro- J'ector.

With my device, the sound may be recorded during the taking of thepictures or it may be extraneous sound coupled with the pictures aftertaking. In either case the sound is perfectly synchronized with thepictures due to the fact that the camera or projector is driven by thesame mechanism that drives the sound record.

Accordingly it becomes an object of this invention to provide meanswhereby a phonograph record may be synchronized with motion pictures.

Another object is to provide means for driving either a camera or aprojector through the record centering pin on a phonograph.

A further object is to provide means whereby the rotation of the soundrecord on a phonograph controls the rotation of a camera or a projectorand also the travel of the sound head over a sound record.

. Other objects and advantages will become apparent as the descriptionproceeds in conjunction with the drawing in which:

Figure 1 is a schematic diagram showing the manner in which my inventionmay be applied to a phonograph;

Figure 2 is a transverse section of the member adapted to be attached tothe centering pin on the phonograph, (taken on line 22 of Figure 3) andFigure 3 is a vertical section of the same, taken online 33 of Figure 2.

By referring to the drawing and particularly to Figure 1 it will be seenthat I have shown my invention in combination with a disk sound record.In this view, A designates the sound record, B the member mentionedhereinbefore which is adapted to fit over the record centering pin, C aflexible drive connection for driving a camera or projector D, E a; feedscrew for controlling the travel of the phonographic sound head F overthe record A, G an amplifier, H a loud speaker and K a microphone, allof which will be more fully described hereinafter.

In Figures 2 and 3, the structure of the member B is fully shown and isseen to comprise a casing H which houses the parts ofthe device. Themember B is adapted to sit upon the record A and the record in turn issupported upon a phonograph tum table I2 (fragrnentarily shown). Theturn table I2 carries the usual record centering pin, designated l3,which as is commonly known rotates with the table and the record.

Rotatably mounted within the casing H is a horizontal gear H whichmeshes with gears 15 and IS on opposite sides thereof. The gear I4 isadapted to be driven by the record centering pin l3 and it is to beunderstood that whereas the gear l4 rotates, the housing H remainsstationary. For this purpose, the gear I4 is attached to a pin H in anysuitable manner and the pin i1 is adapted to be detachably mounted onthe record centering pin l3. The pin I1 is rotatably mounted in thehousing II. In order to give stability to the device and provide adetachable mounting, a base member I8 is placed between the gear 14 andthe record A. The member I8 also rotates with the record and the gear.The pin l1 extends upwardly through the casing I I and slightly above ahub IS on the easing. A sleeve 20 is installed around the pin l1 abovethe gear I! and within the hub l9. This pin is arranged to rotate withinthe hub l9 and will be seen to extend slightly above the upper end ofthe hub and at the lower end to bear against the upper surface of thegear ll. Means is provided for detachably mounting the pin II on therecord centering pin 13 of the phonograph. For this purpose the basemember I8 is provided with a flared opening 2| and the lower end of thepin H is shaped to fit the opening (see Figure 3). The lower end of thepin H is also bored to form a hole 22 which is adapted to receive therecord centering pin l3. The flared wall of the lower end of the pin His then slotted, as indicated by the numeral 24. With such anarrangement, it is evident that as the pin H is pulled upwardly into theflared opening 2i, the expanding end -,of the pin I1 will compress aboutthe pin l3 and form a solid driving connection between the two pins andas has been shown this will drive the gear M. The pin I7 is pulledupwardly by means of a screw threaded nut 25 mounted on the upper end ofthe pin, said nut bearing against the sleeve 20 and the gear Hi beingsplined on the pin ll to permit slight movement of the pin through thegear.

As the gear Ml rotates with the pin l3 and consequently the record A, itdrives the gears l5 and i6 which are meshed with it on opposite sides.The details of mounting the gears l5 and it are unimportant, it beingthought sufficient to state that they are rotatably mounted in thecasing l l and are adapted to be driven by the gear Id. The gear l5 issuitably connected to the flexible drive connection C and may be used todrive either a camera or a projector D'. The gear I6 is a hollow gearand is internally screw threaded to receive the feed screw E. It is thusobvious, that if the feed screw E is held against rotation as the gearl6 rotates in response to rotation of the gear M, the feed screw will befed longitudinally through the gear l6. In order to prevent rotation ofthe feed screw with the gear l6, the outer end is provided with a smallhole 26 adapted to receive a small pin 2? on the sound head F of thephonograph. This pin also serves as a means of attaching the feed screwto the sound head whereby the sound head is caused to travel uniformlyacross the face of the disk A as the feed travels through the gear IS.The feed screw arrangement will find usefulness in recording on blankdisks, that is, on disks that are not pregrooved.

For recording sound with motion pictures, the device B would be mountedupon a blank disk record substantially as shown in Figure 1 and would beconnected to the record centering pin It in the mannerhereinbefore'described. The microphone K would be connected to theamplifier G by means of a switching arrangement generally designated Swhich is diagrammatically shown for the purpose described, and a camerawould be connected to the flexible drive connection C. As

soon as the phonograph starts rotating the disk A, the camera startsoperating and sound may be synchronously recorded with the pictures.

For the reproduction of sound with the pictures, a projector would besubstituted for the camera and a loud speaker would be substituted forthe microphone by means of the switching arrangement S. Then bysynchronizing the start of the film with the start of the record, by anysuitable means such as indicia on the film and record, a perfectsynchronization of sound with the pictures may be had. It is to beunderstood that for reproduction, the feed screw E is not necessary andmay be dispensed with. Accordingly, the device for reproduction purposesonly will find usefulness with the flexible connection only.

Although I have shown and described my invention embodied in a singleform, nevertheless, I do not wish to restrict the invention to thisform. I, therefore, reserve the rights to such modifications andrefinements as come within the scope of the disclosure and the purviewof the appended claims.

I claim:

1. For use with a phonograph having a rotatable record centering pin; adevice having a rotatable gear therein; means for detachablyconnectingsaid gear to said pin; a pair of gears in mesh with said gear,one of said gears being adapted to drive a flexible drive connection andthe other of said gears being hollow and internally screw threaded forreceiving a threaded rod and means for connecting one end of said rod toa phonograph sound head.

2. For use with a phonograph having-a rotatable-record centering pin; adevice having a rotatable gear therein; means for detachably connectingsaid gear to said pin; a pair of gears in mesh with said gear, one ofsaid gears being adapted to drive a flexible drive connection and theother of said gears being internally screw threaded for receiving ascrew threaded rod, said rod having a hole in one end for receiving apin on the phonograph sound head.

3. For use with a phonograph having a rotat-I able record centering pin,a unitary device adapted to be detachably mounted upon said pin, saiddevice having members actuated by said pin for synchronously driving amotion picture camera and controlling the travel of the sound head ofthe phonograph.

EDMUND H. HANSEN.

